As Greeks began pouring into polling booths I got an anxious telephone call from an acquaintance. The night before he had told me of his surprise decision to support the far-left Syriza party, a vote he would not have contemplated at any other time. It wasn't just him but his entire family and most of his friends. All traditional conservatives, they had decided to throw their weight behind Syriza and its young leader, Alexis Tsipras, on the grounds that after years of corrupt establishment rule, with rightists and leftists swinging in and out of government, Greece had got nowhere. "But I beseech you not to mention my name," he said. "This is a revanchist society. I don't want any trouble, and if he wins and doesn't come up with the goods, starting with punishing the old corrupt elite, I'm off."

Few elections have been as electric as this. Faced with the magnitude of what is at stake – the debt-stricken country's future in the euro and ability to withstand more austerity – Greeks are not taking the poll lightly. Throughout the day I have been struck by how voters have agonised over which way to cast ballots. The number of elderly Greeks who have turned up at polling stations dressed in their Sunday best has been impressive. I saw several assisted by relatives, often with walking stick in hand, as they arrived at booths.

"My father insisted on going even though he is 93 and is not now required to vote," said Apostolos Apolamis. "But he wouldn't tell me which way he voted, just that it was important."

Countless Greeks have flown in from overseas. Maria Koundoura, an academic based in Boston, flew in to vote for the first time. "It's vital that Greece gets a government and stability is restored," she said after casting her ballot in her ancestral village outside the northern city of Serres. "Many of my [Greek] colleagues teaching in the USA have flown in. We all care about what happens here. Personally, I have voted for the Democratic Left party because it has said it will do everything to ensure a government is formed and will also put social issues, the cost of austerity, high on the agenda."

Precisely because passions are running so high, the election has been a minefield to report. Mention of some of my own friends swinging to the right raised howls of protests from readers. Many thought it disgraceful that I should choose to "back" the pro-European New Democracy party in such a way – after all, wasn't the conservative party, or indeed any party of the old order, pushing an agenda that was all about retaining privileges?

But the mention was really a way of highlighting the fear that has gripped Greeks who have been assaulted by a barrage of "Drachmageddon" scenarios promulgated mostly by EU leaders prevailing on voters not to elect an anti-austerity government that would push the country out of the eurozone.

After more than two years of crushing austerity, with pay packets and pensions down by as much as 50%, a huge slice of society is desperate. They are backing Syriza, which has vowed to radically renegotiate the terms of the EU-IMF rescue package propping up the bankrupt Greek economy, not because they have nothing to lose but because it is the only party that really does offer the hope its slogan proclaims.

Emotions are also running high among politicians. The office of George Papandreou, Greece's former prime minister, was most put out by the suggestion – erroneously made in the standfirst added to my write-up of an interview with him for the Guardian – that he was supporting his longtime political rival, the New Democrat leader Antonis Samaras (which of course isn't true). In a letter to the Guardian, a senior aide wrote that the slip-up had "created immense confusion among Pasok voters just hours before the polls open. Indeed, many Greek blogs today are reporting the Guardian interview with the title: Papandreou is supporting Samaras!"

The office went so far as to release an audio clip of the interview between myself and Papandreou to highlight its point. The paper of course issued a correction. But journalism is a balancing act, and never more so than at this momentous time for Greece.